Venturi vacuum drawback assemblies and dual orifice venturi valve assemblies

ABSTRACT

Embodiments described herein are generally directed to a venturi valve. The venture valve includes an inlet; an outlet opposite of the inlet; a passage, a primary orifice, and an insert. The passage is positioned between the inlet and the outlet and fluidly coupling the inlet to the outlet. The primary orifice is positioned between the inlet and the outlet and in fluid communication with the passage such that the primary orifice permits fluid to enter the passage. The insert is positioned between the inlet and the outlet, the insert configured to enclose at least a portion of the passage.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 15/828,298 filed on Nov. 30, 2017, which claims priority toU.S. Provisional Patent Application Ser. No. 62/428,089 filed Nov. 30,2016 which are each incorporated herein by reference.

TECHNICAL FIELD

The present disclosure is directed to a venturi vacuum drawbackassemblies for controlling the flow of a fluid, more particularly,venturi vacuum drawback assemblies that include a bypass passage thatcreates a drawback vacuum using a venturi valve.

BACKGROUND

Previously known coolant delivery systems include a coolant supplypassage and a coolant return passage. The coolant supply passage runsfrom a supply of coolant to a device to be cooled. The coolant returnpassage runs from the device to be cooled to a coolant recirculatingdevice. The coolant recirculating device removes the heat added to thecoolant by the device to be cooled and then recirculates the coolant tothe coolant supply.

In addition, the previously known coolant delivery systems areconfigured to close the coolant supply passage upon the detection of aleak. However, any coolant that remains in the coolant supply passagedownstream from the closure will continue to discharge from the leak.The continuous discharge of coolant even after the closure of thecoolant supply passage increases the stop work delay due to repair ofthe leak and clean the discharged coolant.

Accordingly, a need exists for alternative systems and methods fordraining coolant that remains in a coolant delivery system downstreamfrom a closure after leak detection.

SUMMARY

In one embodiment, a venturi valve is provided. The venturi valveincludes an inlet; an outlet opposite of the inlet; a passage, a primaryorifice, and an insert. The passage is positioned between the inlet andthe outlet and fluidly coupling the inlet to the outlet. The primaryorifice is positioned between the inlet and the outlet and in fluidcommunication with the passage such that the primary orifice permitsfluid to enter the passage. The insert is positioned between the inletand the outlet, the insert configured to enclose at least a portion ofthe passage.

In another embodiment, a dual orifice venturi valve is provided. Thedual orifice venturi valve includes an inlet; an outlet opposite of theinlet, a passage, a primary orifice, a secondary orifice, and an insert.The passage is positioned between the inlet and the outlet and fluidlycoupling the inlet to the outlet. The primary orifice is positionedbetween the inlet and the outlet. The secondary orifice is positionedbetween the inlet and the outlet. The insert is positioned between theinlet and the outlet. The insert is configured to enclose a portion ofthe passage. The primary and secondary orifices are each in fluidcommunication with the passage such that the primary and secondaryorifices permit fluid to enter the passage.

In another embodiment, a venturi vacuum system for controlling a flow ofa fluid from a device is provided. The system includes a fluid supplypassage, a fluid return passage, a shutoff valve, a bypass passage, abypass valve, a venturi valve, and an insert. The fluid supply passagesupplies the fluid to the device. The fluid return passage returns thefluid from the device. The shutoff valve is positioned on the fluidsupply passage. The bypass passage includes an inlet and an outlet. Theinlet is connected to the fluid supply passage upstream of the shutoffvalve and the outlet connected to the fluid return passage. The bypassvalve is positioned on the bypass passage. The venturi valve ispositioned on the bypass passage upstream of the bypass valve. Theventuri valve includes a venturi inlet, a venturi outlet, a primaryorifice positioned between the venturi inlet and the venturi outlet, aventuri passage positioned between the venturi inlet and the venturioutlet to fluidly couple the venturi inlet the venturi outlet, and aninsert. The insert is positioned between the inlet and the outlet. Theinsert is configured to enclose a portion of the passage. The primaryorifice is connected to a drawback opening on the fluid supply passageby a conduit. The drawback opening of the fluid supply passage ispositioned downstream of the shutoff valve.

These and additional features provided by the embodiments describedherein will be fully understood in view of the following detaileddescription, in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments set forth in the drawings are illustrative and exemplaryin nature and not intended to limit the subject matter defined by theclaims. The following detailed description of the illustrativeembodiments can be understood when read in conjunction with thefollowing drawings, where like structure is indicated with likereference numerals and in which:

FIG. 1 schematically depicts a venturi vacuum drawback assembly forcontrolling a flow of a fluid from a device, according to one or moreembodiments shown and described herein;

FIG. 2 schematically depicts a partial cross-sectional view of a venturivalve of the venturi vacuum drawback assemblies of FIG. 1 , according toone or more embodiments shown and described herein;

FIG. 3 schematically depicts a venturi vacuum drawback assembly forcontrolling the flow of the fluid from the device, according to one ormore embodiments shown and described herein;

FIG. 4A schematically depicts a partial side view of a venturi valve ofthe venturi vacuum drawback assembly of FIG. 3 , according to one ormore embodiments shown and described herein

FIG. 4B schematically depicts a partial cross-sectional view of theventuri valve of the venturi vacuum drawback assembly taken along thelines B-B of FIG. 4A, according to one or more embodiments shown anddescribed herein;

FIG. 4C schematically depicts a partial cross-sectional view of aventuri valve of the venturi vacuum drawback assembly taken along thelines C-C of FIG. 4B, according to one or more embodiments shown anddescribed herein;

FIG. 5 schematically depicts a venturi vacuum drawback assembly forcontrolling a flow of a fluid from a device, according to one or moreembodiments shown and described herein;

FIG. 6 schematically depicts an isolated view of an insert of a venturivalve according to one or more embodiments shown and described herein;

FIG. 7 schematically depicts a partial cross-sectional view of theventuri valve with the insert of the venturi vacuum drawback assembliesof FIG. 1 , according to one or more embodiments shown and describedherein;

FIG. 8 schematically depicts a partial cross-sectional view of a venturivalve with an insert of the venturi vacuum drawback assemblies of FIG. 3, according to one or more embodiments shown and described herein;

FIG. 9 schematically depicts an isolated partial cross-sectional view ofthe venturi valve of FIG. 6 , according to one or more embodiments shownand described herein;

FIG. 10 schematically depicts a partial cross-sectional view of aventuri valve with an insert of the venturi vacuum drawback assembliesof FIG. 3 with a first opening, according to one or more embodimentsshown and described herein; and

FIG. 11 schematically depicts a partial cross-sectional view of aventuri valve with an insert of the venturi vacuum drawback assembliesof FIG. 3 with a second opening, according to one or more embodimentsshown and described herein.

DETAILED DESCRIPTION

Venturi vacuum drawback assemblies of the present disclosure include afluid supply passage, a fluid return passage, a shutoff valve, a bypasspassage, a bypass valve, and a venturi valve. The fluid supply passagesupplies the fluid to a device. The fluid return passage returns thefluid from the device. The shutoff valve is positioned on the fluidsupply passage. The bypass passage includes an inlet and an outlet. Theinlet is connected to the fluid supply passage upstream of the shutoffvalve, and the outlet connected to the fluid return passage. The bypassvalve is positioned on the bypass passage. The venturi valve ispositioned on the bypass passage upstream of the bypass valve. Theventuri valve includes a venturi inlet, a venturi outlet, an insert anda primary orifice positioned between the venturi inlet and the venturioutlet. The primary orifice is connected to a drawback opening on thefluid supply passage by a conduit. The drawback opening of the fluidsupply passage is positioned downstream of the shutoff valve.

The insert is positioned between the venturi inlet and the venturioutlet and covers at least the inlet orifice, the outlet orifice and theconstricted portion. The insert is generally tubular shaped having anexterior surface and an opposite interior surface. The insert includesan annular groove disposed on the exterior surface. The annular groovehas at least one bore that fluidly couples the exterior surface to theprimary orifice to permit fluid from the primary orifice to enter theconstricted portion. In some embodiments, the at least one bore ispositioned at a position opposite of the conduit such that fluid travelsat least half of the annular groove before entering the at least onebore. In other embodiments, the at least one bore is positioned closerto or further away from the conduit within the annular groove.

Upon movement of the shutoff valve from a normally open position to aclosed position and movement of the bypass valve from a normally closedpositon to an open position, fluid is inhibited from flowing through theshutoff valve to the device and fluid is permitted to flow through thebypass passage including the venturi valve. The flow of fluid throughthe venturi valve creates a vacuum at the primary orifice which drawsback fluid contained in the fluid supply passage downstream of theshutoff valve. The fluid in the fluid supply passage downstream of theshutoff valve is drawn through the conduit into the annular groove andthrough the at least one bore to enter the constricted portion of theventuri valve of the bypass passage so as to exit the bypass passage andinto the fluid return passage.

FIG. 1 generally depicts a coolant delivery system 1 to which a venturivacuum drawback assembly 10 is applied. The coolant delivery system 1includes a device 12 to be cooled by a fluid, for example a coolant. Inthe illustrated embodiment, the device 12 includes a device inlet 14, adevice outlet 16, and a cooling part 18. Fluid flows into the deviceinlet 14 to cool the cooling part 18 and the fluid, heated by thecooling part 18, exits through the device outlet 16. In someembodiments, the cooling part 18 includes a pair of cooling parts 18A.In the illustrated embodiment, the device 12 is a robotic welding deviceand the cooling parts 18A are a pair of weld tips 18A of the roboticwelding device.

Referring to FIG. 1 , the venturi vacuum drawback assembly 10 includes afluid supply 30, a fluid supply passage 22, a fluid return 34, and afluid return passage 24. The device inlet 14 is connected to a fluidsupply 30 by the fluid supply passage 22. The device outlet 16 isconnected to the fluid return 34 by the fluid return passage 24. In someembodiments, the fluid return 34 includes a coolant recirculating device(not shown). The coolant recirculating device, such as refrigerator,removes the heat added to the coolant by the device 12 to be cooled, andthen recirculates the coolant to the fluid supply 30.

The venturi vacuum drawback assembly 10 may also include a flowmeterunit 20 that is provided on at least one of the fluid supply passage 22and the fluid return passage 24. The flowmeter unit 20 includes a supplyoutlet 21 and a supply inlet 26 on the fluid supply passage 22. Thesupply outlet 21 connects to the device inlet 14 of the device 12 by thefluid supply passage 22 downstream of the flowmeter unit 20. The supplyinlet 26 connects to the fluid supply 30 upstream of the flowmeter unit20. The flowmeter unit 20 includes a return inlet 25 and a return outlet32 on the fluid return passage 24. The return inlet 25 connects to thedevice outlet 16 of the device 12 through the fluid return passage 24upstream of the flowmeter unit 20. The return outlet 32 connects to thefluid return 34 through the fluid return passage 24 downstream of theflowmeter unit 20. As described in greater detail below, the flowmeterunit 20 detects leaks from cap loss, hose burst, or inadvertent shutoffand outputs a leak signal upon the detection of a leak.

The venturi vacuum drawback assembly 10 may also include a shutoff valve28 that is positioned on the fluid supply passage 22 upstream of theflowmeter unit 20. Specifically, the shutoff valve 28 is provided on thefluid supply passage 22 upstream of the supply inlet 26. The shutoffvalve 28 is switchable between a normally open position and a closedposition. In the open position, the shutoff valve 28 allows coolant fromthe fluid supply 30 to flow into the supply inlet 26. In the closedposition, the shutoff valve 28 inhibits fluid flowing from the fluidsupply 30 through the shutoff valve 28 to the supply inlet 26.

The venturi vacuum drawback assembly 10 also includes a bypass passage36, a bypass valve 42, a venturi valve 44, and a conduit 46 thatconnects the venturi valve 44 to the fluid supply passage 22 downstreamof the shutoff valve 28. The bypass passage 36 includes a bypass inlet38 and a bypass outlet 40. The bypass inlet 38 is positioned on thefluid supply passage 22 upstream of the shutoff valve 28. The bypassoutlet 40 is positioned on the fluid return passage 24 downstream of thereturn outlet 32.

The bypass valve 42 is switchable between a normally closed position andan open position. In the closed position, the bypass valve 42 inhibitsfluid from passing through the bypass passage 36. In the open position,the bypass valve 42 allows fluid to flow through the bypass passage 36to bypass the device 12. Specifically, the fluid that flows through thebypass passage 36 bypasses the supply inlet 26, the flowmeter unit 20,the supply outlet 21, the device inlet 14, the device 12, the coolingpart 18, the device outlet 16, the return inlet 25, and the returnoutlet 32 so as to enter the fluid return passage 24.

The venturi valve 44 is positioned on the bypass passage 36 between thebypass inlet 38 and the bypass valve 42. The venturi valve 44 includes aventuri inlet 48, a venturi outlet 50, and a primary orifice 52positioned between the venturi inlet 48 and the venturi outlet 50.

A drawback opening 54A is provided on the fluid supply passage 22downstream of the flowmeter unit 20. Specifically, the drawback opening54A is positioned on the fluid supply passage 22 between the supplyoutlet 21 and the device inlet 14. The conduit 46 connects the primaryorifice 52 to the drawback opening 54A. In some embodiments, a checkvalve 45 is positioned between the drawback opening 54A and the primaryorifice 52 of the venturi valve 44.

In some embodiments, a drawback opening 54B is provided on the fluidreturn passage 24 upstream of the flowmeter unit 20. Specifically, thedrawback opening 54B is positioned on the fluid return passage 24between the return inlet 25 and the device outlet 16. In someembodiments, the conduit 46 includes a junction 55 that splits theconduit 46 to connect the primary orifice 52 to at least one of thedrawback opening 54A and the drawback opening 54B. The junction 55splits the conduit 46 to connect the primary orifice 52 to both thedrawback opening 54A and the drawback opening 54B. A check valve 45 ispositioned between the junction 55 and the primary orifice 52 of theventuri valve 44 so as to prevent fluid from flowing from the primaryorifice 52 of the venturi valve 44 to the drawback opening 54A and 54B.In some other embodiments, the check valve 45 is positioned between thejunction 55 and the drawback opening 54A and a check valve 45 ispositioned between the junction 55 and the drawback opening 54B.

Referring to FIG. 2 , the venturi valve 44 includes a first constrictedportion 60A and a second constricted portion 60B. The first constrictedportion 60A includes an inlet orifice 62 and an outlet orifice 64. Theprimary orifice 52 is positioned at the first constricted portion 60Abetween the inlet orifice 62 and the outlet orifice 64. As such, theinlet orifice 62 is the opening of the first constricted portion 60Athat is in fluid communication with the second constricted portion 60B.The second constricted portion 60B is in fluid communication with theventuri inlet 48. The outlet orifice 64 is the opening of the firstconstricted portion 60A that is in communication with the venturi outlet50.

In some embodiments, the venturi valve 44 further includes an inletpassage 62A and an outlet passage 64A. The inlet passage 62A extendsbetween second constricted portion 60B and the venturi inlet 48. Theoutlet passage 64A extends between the outlet orifice 64 and the venturioutlet 50.

The primary orifice 52 includes a diameter D1 at the first constrictedportion 60A. The inlet orifice 62 includes a diameter D2 at the junctionbetween the first constricted portion 60A and the second constrictedportion 60B. The outlet orifice 64 includes a diameter D3 at the firstconstricted portion 60A. The inlet orifice 62 is the junction of thefirst constricted portion 60A and the second constricted portion 60Bwhere the diameter D2 changes from to the diameter D3. In someembodiments, the first constricted portion 60A includes the diameter D3and the second constricted portion 60B includes the diameter D2.

In some embodiments, the diameter D3 of the outlet orifice 64, thediameter D1 of the primary orifice 52, and the diameter D2 of the inletorifice 62 are dimensioned such that an area of outlet orifice 64 isequal to a sum of an area of the primary orifice 52 and an area of theinlet orifice 62. As such, a velocity of the fluid flowing through theinlet orifice 62 is substantially equal to a velocity of the fluidflowing through the primary orifice 52 which is substantially equal to avelocity of the fluid flowing through the outlet orifice 64.

In some other embodiments, the diameter D3 of the outlet orifice 64, thediameter D1 of the primary orifice 52, and the diameter D2 of the inletorifice 62 are dimensioned such that the area of outlet orifice 64 isless than the sum of the area of the primary orifice 52 and the area ofthe inlet orifice 62. For example, the area of the outlet orifice 64 isless than the sum of the area of the primary orifice 52 and the area ofthe inlet orifice 62 by at least 0.1%, such as at least 1%, such as atleast 5%, such as at least 10%.

In some embodiments, the first constricted portion 60A is generallycylindrically shaped having the diameter D3, and the second constrictedportion 60B is generally cylindrical shaped having the diameter D2. Assuch, the inlet orifice 62 at the junction of the first constrictedportion 60A and the second constricted portion 60B has the diameter D2and the outlet orifice 64 has the diameter D3.

In some embodiments, the first constricted portion 60A and the secondconstricted portion 60B constrict the diameter of the venturi valve 44so as to reduce a pressure as the fluid flows through the secondconstricted portion 60 and then the first constricted portion 60A whichcreates a vacuum at the primary orifice 52 located in the firstconstricted portion. In some embodiments, the first constricted portion60A and the second constricted portion 60B are dimensioned such that anarea of the outlet orifice 64 is equal to or greater than a sum of anarea of the inlet orifice 62 and an area of the primary orifice 52.

Referring back to FIG. 1 , the flowmeter unit 20 is configured to detectdifferences in flow between the fluid flowing through the fluid supplypassage 22 and the fluid return passage 24. Specifically, a supplyflowmeter 20A is provided between the supply outlet 21 and a supplyinlet 26 and a return flowmeter 20B is provided between the return inlet25 and the return outlet 32. The flowmeter unit includes an electroniccontrol unit 70.

Examples of a flowmeter unit 20 that may be used in the disclosedventuri vacuum drawback assembly 110 include, but are not limited to,the Delta Point®, Ethernet Delta Point®, 24V DC Delta Point®, 120V ACDelta Point®, and DeviceNet Delta Point®, sold by Rocon LLC of HazelPark, Mich. It will be appreciated, of course, that other flowmeterunits may also be used in conjunction with the venturi vacuum drawbackassembly 10.

The electronic control unit 70 is electronically connected to theshutoff valve 28 and the bypass valve 42. Specifically, the electroniccontrol unit 70 is configured to control the operation of the shutoffvalve 28 between the normally open position and the closed position. Theelectronic control unit 70 is further configured to control theoperation of the bypass valve 42 between the normally closed positionand the open position. In some embodiments, the shutoff valve 28 and thebypass valve 42 are electronically controlled solenoid valves that arecontrolled by the electronic control unit 70.

In some embodiments, the electronic control unit 70 includes a processor72 and a memory component 74 coupled to the processor 72. The processor72 is a central processing unit (CPU). The processor 72 includesprocessing components operable to receive and execute instructions fromthe memory component 74. The memory component 74 stores detection logic74A and control logic 74B. The detection logic 74A and the control logic74B may each include a plurality of different pieces of logic, each ofwhich may be embodied as a computer program, firmware, and/orsoftware/hardware.

In some embodiments, the memory component 74 is configured as volatileand/or nonvolatile memory and as such may include random access memory(SRAM, DRAM, and/or other types of RAM), flash memory, secure digital(SD) memory, registers, compact discs, digital versatile discs (DVD),and/or other types of nontransitory computer readable mediums. Dependingon the particular embodiments, these nontransitory computer readablemediums may reside within the electronic control unit 70 and/or externalto the electronic control unit 70 and the flowmeter unit 20.

The detection logic 74A is executable by the processor 72 to detect oneor more signals output from the supply flowmeter 20A and the returnflowmeter 20B. For example, the detection logic 74A is configured tocause the processor 72 to determine a presence or absence of a leak inthe coolant delivery system 1, specifically, a leak in at least one ofthe fluid supply passage 22, the device 12, including device inlet 14and the device outlet 16, and the fluid return passage 24 based on thesignals output from at least one of the supply flowmeter 20A and thereturn flowmeter 20B. Specifically, processor 72 determines the presenceor absence of the leak based on output signals from the supply flowmeter20A and the return flowmeter 20B that indicate the flowrates of thefluid supply passage 22 and the fluid return passage 24, respectively.

The control logic 74B is executed by the processor 72 to controloperation of the shutoff valve 28 and the bypass valve 42 based on thedetermination of the presence or absence of a leak in the coolantdelivery system 1 by the processor 72. In some embodiments, when theprocessor 72 has determined the absence of a leak, the control logic 74Bis executed by the processor 72 to control the shutoff valve 28 into thenormally open position and the control logic 74B controls the bypassvalve 42 in the normally closed position.

In order to facilitate a better understanding of the venturi vacuumdrawback assembly 10, a discussion of the operation of the venturivacuum drawback assembly 110 will be provided. During operation in whichthe processor 72 determines the absence of a leak, the coolant deliverysystem 1 operates to deliver fluid from the fluid supply 30 to thedevice 12 through the fluid supply passage 22 and returns the fluid fromthe device 12 through the fluid return passage 24 to the recirculationdevice connected to the fluid return 34. Specifically, during suchoperation, the shutoff valve 28 is in the normally open position and thebypass valve 42 is in the normally closed position. As fluid flowsthrough the fluid supply passage 22, the fluid is prevented from flowingthrough the bypass passage 36 as the bypass valve 42 is in the normallyclosed position.

During operation in which the processor 72 determines the presence of aleak, the venturi vacuum drawback assembly 10 operates to control theflow of fluid from the device 12. Specifically, upon the processor 72determining the presence of a leak based on the one or more signalsoutput from the supply flowmeter 20A and the return flowmeter 20B anddetected by the detection logic 74A, the control logic 74B is executedby the processor 72 to control the shutoff valve 28 from the normallyopen position to the closed position and to control the bypass valve 42from the normally closed position to the open position.

In some embodiments, the processor 72 executes the control logic 74B toswitch the bypass valve 42 from the normally closed position to the openposition simultaneously with the switching of the shutoff valve 28 fromthe normally open position to the closed position. In some embodiments,the processor 72 executes the control logic 74B to switch the bypassvalve 42 from the normally closed position to the open position after anelapse of a preset time period after switching of the shutoff valve 28from the normally open position to the closed position.

In the closed position, the shutoff valve 28 prevents fluid from flowingfrom the fluid supply 30 through the shutoff valve 28 to the device 12.As fluid is prevented from flowing in the fluid supply passage 22,downstream of the shutoff valve 28, additional fluid is prevented frombeing discharged through the leak. As the bypass valve 42 is in the openposition, fluid is permitted to flow through the bypass passage 36 fromthe bypass inlet 38 on the fluid supply passage 22 upstream of theshutoff valve 28 to the bypass outlet 40 on the fluid return passage 24downstream of the return outlet 32.

As such, fluid flows through the bypass passage 36 including the venturivalve 44. Due to the venturi effect of the venturi valve 44, a pressurein the venturi valve 44 upstream of the primary orifice 52 is higherthan the pressure downstream of the primary orifice 52 due to the changein cross-sectional area at the first constricted portion 60A and thesecond constricted portion 60B. Accordingly, the fluid remaining in thefluid supply passage 22 downstream of the shutoff valve 28 is at ahigher pressure than the pressure at the primary orifice 52 and thefluid moves from the area of high pressure to the area of low pressureto drain the fluid that remains in the fluid supply passage 22 throughthe venturi valve 44 so as to exit through the fluid return passage 24.Similarly, the fluid remaining in the fluid return passage 24 upstreamof the flowmeter is at a higher pressure than the pressure at theprimary orifice 52 and the fluid moves from the area of high pressure tothe area of low pressure to drain the fluid that remains in the fluidreturn passage 22 through the venturi valve 44 so as to exit through thefluid return passage 24.

As such, the decrease in pressure creates a vacuum at the primaryorifice 52 allowing the fluid that remains in the fluid supply passage22 downstream of the shutoff valve 28 to be drawn through drawbackopening 54A and into the primary orifice 52 via the conduit 46. Fluiddrawn through the primary orifice 52 exits the venturi valve 44 via theventuri outlet 50 and enters the fluid return passage 24 via the bypassoutlet 40. Therefore, the remaining fluid in the fluid supply passage 22downstream of the shutoff valve 28 will not discharge through the leak,such as through the pair of cooling parts 18A, due to the vacuum effectof the venturi valve 44.

Similarly, the decrease in pressure creates a vacuum at the primaryorifice 52 allowing the fluid that remains in the fluid return passage24 downstream of the device 12 to be drawn through drawback opening 54Band into the primary orifice 52 via the conduit 46. Fluid drawn throughthe primary orifice 52 exits the venturi valve 44 via the venturi outlet50 and enters the fluid return passage 24 via the bypass outlet 40.Therefore, the remaining fluid in the fluid return passage 24 downstreamof the device 12 will not discharge through the leak due to the vacuumeffect of the venturi valve 44.

In some embodiments, the venturi valve 44 not only draws back the fluidin the fluid supply passage 22 that is upstream and/or downstream of theleak and draws back the fluid in the fluid return passage 24 that isupstream and/or downstream of the leak.

Referring to FIG. 3 , a venturi vacuum drawback assembly is generallyillustrated at 10′. The venturi vacuum drawback assembly 10′ is similarto the venturi vacuum drawback assembly 10 except that the venturivacuum drawback assembly 10 includes a dual orifice venturi valve 144, asupply conduit 46A and a return conduit 46B.

The dual orifice venturi valve 144 is positioned on the bypass passage36 between the bypass inlet 38 and the bypass valve 42. The dual orificeventuri valve 144 includes a venturi inlet 148, a venturi outlet 150, aprimary orifice 152A, and a secondary orifice 152B. The primary orifice152A and the secondary orifice 152B are positioned between the venturiinlet 148 and the venturi outlet 150. The primary orifice 152A isfluidly connected to the drawback opening 54A by the supply conduit 46Aand the secondary orifice 152B is connected to the drawback opening 54Bby the return conduit 46B. In some embodiments, check valve 45 ispositioned on the supply conduit 46A between the primary orifice 152Aand the drawback opening 54A and a check valve 45 is positioned on thereturn conduit 46B between the secondary orifice 152B and the drawbackopening 54B.

Referring to FIGS. 4A, 4B, and 4C, the dual orifice venturi valve 144includes a first constricted portion 160A and a second constrictedportion 160B. The first constricted portion 160A includes an inletorifice 162 and an outlet orifice 164. The primary orifice 152A and thesecondary orifice 152B are positioned at the first constricted portion160A between the inlet orifice 162 and the outlet orifice 164. The inletorifice 162 is the junction of the first constricted portion 160A andthe second constricted portion 60B. As such, the inlet orifice 162 isthe opening of the first constricted portion 160A that is incommunication with the second constricted portion 160B. The secondconstricted portion 60B is in communication with the venturi inlet 148.The outlet orifice 164 is the opening of the first constricted portion160A that is in communication with the venturi outlet 150.

In some embodiments, the dual orifice venturi valve 144 includes aninlet passage 162A and an outlet passage 164A. The inlet passage 162Aextends between the second constricted portion 160B and the venturiinlet 148. The outlet passage 164A extends between the outlet orifice164 and the venturi outlet 150.

Referring to FIG. 4B, the primary orifice 152A includes a diameter D1′at the first constricted portion 160A. Referring to FIG. 4C, thesecondary orifice 152B includes a diameter D4′ at the first constrictedportion 160A. Referring to FIGS. 4B, and 4C, the inlet orifice 162includes a diameter D2′ at the first constricted portion 160A. Theoutlet orifice 164 includes a diameter D3′. As such, the inlet orifice162 is the junction of the first constricted portion 160A and the secondconstricted portion 160B where the diameter D2 changes from to thediameter D3. The inlet orifice 162 is the opening of the firstconstricted portion 160A that is in communication with the secondconstricted portion 160B. The second constricted portion 160B is incommunication with the venturi inlet 148. The outlet orifice 164 is theopening of the first constricted portion 160A that is in communicationwith the venturi outlet 150.

In some embodiments, the dual orifice venturi valve 144 includes aninlet passage 162A and an outlet passage 164A. The inlet passage 162Aextends between second constricted portion 160B and the venturi inlet148. The outlet passage 164A extends between the outlet orifice 164 andthe venturi outlet 150.

In some embodiments, the diameter D3′ of the outlet orifice 164, thediameter D 1′ of the primary orifice 152A, the diameter D4′ of thesecondary orifice 152B, and the diameter D2′ of the inlet orifice 62 aredimensioned such that an area of outlet orifice 164 is equal to a sum ofan area of the primary orifice 152A, the secondary orifice 152B, and anarea of the inlet orifice 162.

In some embodiments, the diameter D3′ of the outlet orifice 164, thediameter D 1′ of the primary orifice 152A, the diameter D4′ of thesecondary orifice 152B, and the diameter D2′ of the inlet orifice 62 aredimensioned such that the area of outlet orifice 164 is less than thesum of the area of the primary orifice 152A, the secondary orifice 152B,and the area of the inlet orifice 162. For example, the area of theoutlet orifice 164 is less than the sum of the area of the primaryorifice 152A, the area of the secondary orifice 152B, and the area ofthe inlet orifice 62 by at least 0.1%, such as at least 1%, such as atleast 5%, such as at least 10%.

As such, a velocity of the fluid flowing through the inlet orifice 162is substantially equal to a velocity of the fluid flowing through theprimary orifice 152A and the velocity of the fluid flowing through thesecondary orifice 52B which is substantially equal to a velocity of thefluid flowing through the outlet orifice 164.

In some embodiments, the first constricted portion 160A is generallycylindrically shaped having the diameter D3′, and the second constrictedportion 160B is generally cylindrically shaped having the diameter D2′.As such, the inlet orifice 162 at the junction between the firstconstricted portion 160A and the second constricted portion 160B has thediameter D2′ the outlet orifice 164 end has the diameter D3′.

In some embodiments, the first constricted portion 160A and the secondconstricted portion constrict the diameter of the dual orifice venturivalve 144 so as to reduce a pressure which creates a vacuum at theprimary orifice 152A and the secondary orifice 152B. In someembodiments, the first constricted portion 160A and the secondconstricted portion 160B are dimensioned such that an area of the outletorifice 164 is equal to or greater than a sum of an area of the primaryorifice 152A, an area of the secondary orifice 152B, and an area of theinlet orifice 162.

Referring to FIGS. 4A, 4B, and 4C, fluid flows through the dual orificeventuri valve 144 in a flow direction A from the venturi inlet 148towards the venturi outlet 150. In some embodiments, the dual orificeventuri valve 144 is oriented such fluid flows through the primaryorifice 152A in a first direction and fluid flows through the secondaryorifice 152B in a second direction. The first direction is generallyperpendicular to the flow direction A and the second direction isgenerally perpendicular to the flow direction A. The first direction isalso generally perpendicular to the second direction.

In order to facilitate a better understanding of the venturi vacuumdrawback assembly 10′, a discussion of the operation of the venturivacuum drawback assembly 10′ will be provided. During operation in whichthe processor 72 determines the absence of a leak, the coolant deliverysystem 1 operates to deliver fluid from the fluid supply 30 to thedevice 12 through the fluid supply passage 22 and returns the fluid fromthe device 12 through the fluid return passage 24 to the recirculationdevice connected to the fluid return 34. Specifically, during suchoperation, the shutoff valve 28 is in the normally open position and thebypass valve 42 is in the normally closed position. As fluid flowsthrough the fluid supply passage 22, the fluid is prevented from flowingthrough the bypass passage 36 as the bypass valve 42 is in the normallyclosed position.

During operation in which the processor 72 determines the presence of aleak, the venturi vacuum drawback assembly 10 operates to control theflow of fluid from the device 12. Specifically, upon the processor 72determining the presence of a leak based on the one or more signalsoutput from the supply flowmeter 20A and the return flowmeter 20B anddetected by the detection logic 74A, the control logic 74B is executedby the processor 72 to control the shutoff valve 28 from the normallyopen position to the closed position and to control the bypass valve 42from the normally closed position to the open position.

In some embodiments, the processor 72 executes the control logic 74B toswitch the bypass valve 42 from the normally closed position to the openposition simultaneously with the switching of the shutoff valve 28 fromthe normally open position to the closed position. In some embodiments,the processor 72 executes the control logic 74B to switch the bypassvalve 42 from the normally closed position to the open position after anelapse of a preset time period after switching of the shutoff valve 28from the normally open position to the closed position.

In the closed position, the shutoff valve 28 prevents fluid from flowingfrom the fluid supply 30 through the shutoff valve 28 to the device 12.As fluid is prevented from flowing in the fluid supply passage 22,downstream of the shutoff valve 28, additional fluid is prevented frombeing discharged through the leak. As the bypass valve 42 is in the openposition, fluid is permitted to flow through the bypass passage 36 fromthe bypass inlet 38 on the fluid supply passage 22 upstream of theshutoff valve 28 to the bypass outlet 40 on the fluid return passage 24downstream of the return outlet 32.

As such, fluid flows through the bypass passage 36 including the dualorifice venturi valve 144. Due to the venturi effect of the dual orificeventuri valve 144, a pressure in the dual orifice venturi valve 144upstream of the primary orifice 152A and the secondary orifice 152B ishigher than the pressure downstream of the primary orifice 152A due tothe change in cross-sectional area at the first constricted portion 160Aand the second constricted portion 160B. Accordingly, the fluidremaining in the fluid supply passage 22 downstream of the shutoff valve28 is at a higher pressure than the pressure at the primary orifice 152Aand the fluid moves from the area of high pressure to the area of lowpressure to drain the fluid that remains in the fluid supply passage 22through the dual orifice venturi valve 144 so as to exit through thefluid return passage 24. Similarly, the fluid remaining in the fluidreturn passage 24 upstream of the flowmeter 20 is at a higher pressurethan the pressure at the secondary orifice 152B and the fluid moves fromthe area of high pressure to the area of low pressure to drain the fluidthat remains in the fluid return passage 24 through the dual orificeventuri valve 144 so as to exit through the fluid return passage 24.

As such, the decrease in pressure creates a vacuum at the primaryorifice 152A allowing the fluid that remains in the fluid supply passage22 downstream of the shutoff valve 28 to be drawn through drawbackopening 54A and into the primary orifice 52 via the supply conduit 46A.Fluid drawn through the primary orifice 52 exits the dual orificeventuri valve 144 via the venturi outlet 50 and enters the fluid returnpassage 24 via the bypass outlet 40. Therefore, the remaining fluid inthe fluid supply passage 22 downstream of the shutoff valve 28 will notdischarge through the leak due to the vacuum effect of the venturi valve44.

Similarly, the decrease in pressure creates a vacuum at the secondaryorifice 152B allowing the fluid that remains in the fluid return passage24 downstream of the device 12 to be drawn through drawback opening 54Band into the secondary orifice 152B via the return conduit 46B. Fluiddrawn through the secondary orifice 152B exits the dual orifice venturivalve 144 via the venturi outlet 50 and enters the fluid return passage24 via the bypass outlet 40. Therefore, the remaining fluid in the fluidreturn passage 24 downstream of the device 12 will not discharge throughthe leak due to the vacuum effect of the venturi valve 44.

In some embodiments, the dual orifice venturi valve 144 not only drawsback the fluid in the fluid supply passage 22 that is upstream and/ordownstream of the leak and draws back the fluid in the fluid returnpassage 24 that is upstream and/or downstream of the leak.

Referring to FIG. 5 , a venturi vacuum drawback assembly is generallyillustrated at 110. The venturi vacuum drawback assembly 110 is similarto the venturi vacuum drawback assembly 10′ except that the venturivacuum drawback assembly 110 includes a secondary fluid supply passage122, a secondary fluid return passage 124, a secondary flowmeter unit120, a secondary shutoff valve 128, and secondary conduit 146.

In some embodiments, the secondary fluid supply passage 122 extends fromthe fluid supply passage 22, upstream of the flowmeter unit 20, theshutoff valve 28 and the bypass inlet 38, to a secondary device inlet114 of the device 12. The secondary fluid return passage 124 extendsfrom a secondary device outlet 116 of the device 12 to the fluid returnpassage 24 downstream of the flowmeter unit 20 and bypass outlet 40. Insome embodiments, fluid is directed to one of the pair of cooling parts18A by the device inlet 14 and the device outlet 16 and fluid isdirected to the other of the pair of cooling parts 18A by the secondarydevice inlet 114 and the secondary device outlet 116.

The secondary flowmeter unit 120 includes a secondary supply outlet 121and a secondary supply inlet 126 on the secondary fluid supply passage122. The secondary supply outlet 121 connects to the secondary deviceinlet 114 of the device 12 by the secondary fluid supply passage 122downstream of the secondary flowmeter unit 120. The secondary supplyinlet 126 connects the secondary fluid supply passage 122 downstream ofthe secondary flowmeter unit 120. The secondary supply inlet 126 isconnected to the fluid supply 30 by the secondary fluid supply passage122 and the fluid supply passage 22.

The secondary flowmeter unit 120 includes a secondary return inlet 125and a secondary return outlet 132 on the secondary fluid return passage124. The secondary return inlet 125 connects to the secondary deviceoutlet 116 of the device 12 through the secondary fluid return passage124 upstream of the secondary flowmeter unit 120. The secondary returnoutlet 132 connects to the fluid return 34 through the secondary fluidreturn passage 124 downstream of the secondary flowmeter unit 120 andthe fluid return passage 24.

In some other embodiments, the secondary device inlet 114 and thesecondary device outlet 116 are provided on a secondary device 112having a cooling part 118. The secondary fluid supply passage 122extends from the fluid supply passage 22, upstream of the flowmeter unit20, the shutoff valve 28 and the bypass inlet 38, to a secondary deviceinlet 114 of the secondary device 112. The secondary fluid returnpassage 124 extends from a secondary device outlet 116 of the secondarydevice 112 to the fluid return passage 24 downstream of the flowmeterunit 20 and bypass outlet 40.

The secondary flowmeter unit 120 is configured to detect differences inflow between the fluid flowing through the secondary fluid supplypassage 122 and the secondary fluid return passage 124. Specifically, asecondary supply flowmeter 120A is provided between the secondary supplyoutlet 121 and a secondary supply inlet 126 and a secondary returnflowmeter 120B is provided between the secondary return inlet 125 and asecondary return outlet 132. As described in greater detail above, thesecondary flowmeter unit 120 detects leaks from cap loss, hose burst, orinadvertent shutoff and outputs a leak signal upon the detection of aleak similarly to the flowmeter unit 20.

The secondary shutoff valve 128 is positioned on the secondary fluidsupply passage 122 upstream of the secondary flowmeter unit 120.Specifically, the secondary shutoff valve 128 is provided on thesecondary fluid supply passage 122 upstream of the secondary supplyinlet 126. The secondary shutoff valve 128 is switchable between anormally open position and a closed position. In the normally openposition the secondary shutoff valve 128 allows fluid from the secondaryfluid supply passage 122 to flow into the secondary supply inlet 126. Inthe closed position the secondary shutoff valve 128 prevents fluidflowing from the secondary fluid supply passage 122 through thesecondary shutoff valve 128 to the secondary supply inlet 126.

The secondary conduit 146 extends between a secondary drawback opening154 formed on the secondary fluid supply passage 122 and the dualorifice venturi valve 144. The secondary drawback opening 154 isprovided on the secondary fluid supply passage 122 downstream of thesecondary flowmeter unit 120. Specifically, the secondary drawbackopening 154 is positioned on the secondary fluid supply passage 122between the secondary supply outlet 121 and the secondary device inlet114.

The dual orifice venturi valve 144 is positioned on the bypass passage36 between the bypass inlet 38 and the bypass valve 42. The primaryorifice 152A of the dual orifice venturi valve 144 is connected to thedrawback opening 54 by the conduit 46 and the secondary orifice 152B ofthe dual orifice venturi valve 144 is connected to the secondarydrawback opening 154 by the secondary conduit 146.

In some embodiments, the conduit 46 include a junction, similar to thejunction 55 of FIG. 1 to connect the conduit 46 to the drawback 54 onthe fluid supply passage 22 and a drawback opening on the fluid returnpassage 24. In some embodiments, the secondary conduit 146 include ajunction, similar to the junction 55 of FIG. 1 , to connect thesecondary conduit 146 to the drawback 154 on the secondary fluid supplypassage 122 and a drawback opening on the secondary fluid return passage124. In some other embodiments, both the conduit 46 and the secondaryconduit 146 include junctions, similar to the junction 55 of FIG. 1 , toconnect the conduit 46 to the drawback 54 on the fluid supply passage 22and a drawback opening on the fluid return passage 24 to connect thesecondary conduit 146 to the drawback 154 on the secondary fluid supplypassage 122 and a drawback opening on the secondary fluid return passage124.

In some embodiments, the conduit 46 includes a check valve positionedbetween the drawback opening 54 and the primary orifice 152A of the dualorifice venturi valve 144. In some embodiments, the secondary conduit146 includes a check valve positioned between the secondary drawbackopening 154 and the secondary orifice 152B of the dual orifice venturivalve 144. In some other embodiments, the conduit 46 includes a checkvalve positioned between the junction and the primary orifice 152A andthe secondary conduit 146 includes a check valve positioned between thejunction and the secondary orifice 152B.

In some embodiments, the venturi vacuum drawback assembly 110 includes aprimary conduit valve 80 and a secondary conduit valve 180. The primaryconduit valve 80 is positioned on the conduit 46 between the drawbackopening 54 and the primary orifice 152A. The primary conduit valve 80 ismovable between a normally closed position, which prevents the flow offluid through the primary conduit valve 80, and an open position, whichpermits the flow of fluid through the primary conduit valve 80. Thesecondary conduit valve 180 is positioned on the secondary conduit 146between the secondary drawback opening 154 and the secondary orifice152B. The secondary conduit valve 180 is movable between a normallyclosed position, which prevents the flow of fluid through the secondaryconduit valve 180, and an open position, which permits the flow of fluidthrough the secondary conduit valve 180.

The electronic control unit 70 is electronically connected to secondaryflowmeter unit 120 similar to the flowmeter unit 20. The electroniccontrol unit 70 is also electronically connected to the shutoff valve28, the secondary shutoff valve 128, the bypass valve 42, the primaryconduit valve 80, and the secondary conduit valve 180. Specifically, theelectronic control unit 70 is configured to control the operation of theshutoff valve 28 between the normally open position and the closedposition. The electronic control unit 70 is further configured tocontrol the operation of the bypass valve 42 between the normally closedposition and the open position. The electronic control unit 70 isconfigured to control the operation of the secondary shutoff valve 128between the normally open position and the closed position. Theelectronic control unit 70 is further configured to control theoperation of the primary conduit valve 80 and the secondary conduitvalve 180 between the normally closed position and the open position. Insome embodiments, the shutoff valve 28, the secondary shutoff valve 128,the bypass valve 42, the primary conduit valve 80, and the secondaryconduit valve 180 are electronically controlled solenoid valves that arecontrolled by the electronic control unit 70.

The detection logic 74A is executed by the processor 72 to detect one ormore signals output from the supply flowmeter 20A, the return flowmeter20B, the secondary supply flowmeter 120A, and the secondary returnflowmeter 120B. For example, the detection logic 74A is configured tocause the processor 72 to determine a presence or absence of a leak inthe coolant delivery system 101, specifically, a leak in at least one ofthe fluid supply passage 22, the device 12, including device inlet 14and the device outlet 16, and the fluid return passage 24 based on thesignals output from at least one of the supply flowmeter 20A and thereturn flowmeter 20B. Specifically, processor 72 determines the presenceor absence of the leak based on output signals from the supply flowmeter20A and the return flowmeter 20B that indicate the flowrates of thefluid supply passage 22 and the fluid return passage 24, respectively.

Further, the detection logic 74A is configured to cause the processor 72to determine a presence or absence of a leak in at least one of thesecondary fluid supply passage 122, the secondary device inlet 114, thesecondary device outlet 116, and the secondary fluid return passage 124based on the signals output from at least one of the secondary supplyflowmeter 120A and the secondary return flowmeter 120B. Specifically,processor 72 determines the presence or absence of the leak based onoutput signals from the secondary supply flowmeter 120A and thesecondary return flowmeter 120B that indicate the flowrates of thesecondary fluid supply passage 122 and the secondary fluid returnpassage 124, respectively.

The control logic 74B is executed by the processor 72 to controloperation of the shutoff valve 28, the secondary shutoff valve 128, andthe bypass valve 42 based on the determination of the presence orabsence of a leak in the coolant delivery system 101. In someembodiments, when the processor 72 has determined the absence of a leak,the control logic 74B maintains the shutoff valve 28 in the normallyopen position, the secondary shutoff valve 128 in the normally openposition, and the bypass valve 42 in the normally closed position.

In order to facilitate a better understanding of the venturi vacuumdrawback assembly 110, a discussion of the operation of the venturivacuum drawback assembly 110 will be provided. During operation in whichthe processor 72 determines the absence of a leak, the coolant deliverysystem 101 operates to deliver fluid from the fluid supply 30 to thedevice 12 through the fluid supply passage 22 and the secondary fluidsupply passage 122 and returns the fluid from the device 12 through thefluid return passage 24 and the secondary fluid return passage 124 tothe recirculation device connected to the fluid return 34. Specifically,during such operation, the shutoff valve 28 is in the normally openposition, the secondary shutoff valve 128 is in the normally openposition, and the bypass valve 42 is in the normally closed position. Asfluid flows through the fluid supply passage 22, the fluid is preventedfrom flowing through the bypass passage 36 as the bypass valve 42 is inthe normally closed position.

During operation in which the processor 72 determines the presence of aleak, the venturi vacuum drawback assembly 110 operates to control theflow of fluid from the device 12. Specifically, upon the processor 72determining the presence of a leak based on the one or more signalsoutput from the supply flowmeter 20A, the return flowmeter 20B, thesecondary supply flowmeter 120A, and the secondary return flowmeter 120Band detected by the detection logic 74A, the control logic 74B isexecuted by the processor 72 to control the shutoff valve 28 from thenormally open position to the closed position, to control the secondaryshutoff valve 128 from the normally open position to the closedposition, and to control the bypass valve 42 from the normally closedposition to the open position.

In some embodiments, the processor 72 executes the control logic 74B toswitch the bypass valve 42 from the normally closed position to the openposition simultaneously with the switching of the shutoff valve 28 andthe secondary shutoff valve 128 from the normally open position to theclosed position. In some embodiments, the processor 72 executes thecontrol logic 74B to switch the bypass valve 42 from the normally closedposition to the open position after an elapse of a preset time periodafter switching of the shutoff valve 28 and the secondary shutoff valve128 from the normally open position to the closed position.

In the closed position, the shutoff valve 28 prevents fluid from flowingfrom the fluid supply 30 through the shutoff valve 28 to the device 12,and the secondary shutoff valve 128 prevents fluid from flowing from thesecondary fluid supply passage 122 through the secondary shutoff valve128 to the device. As fluid is prevented from flowing in the fluidsupply passage 22, downstream of the shutoff valve 28, and fluid isprevented from flowing in the secondary fluid supply passage 122,downstream of the secondary shutoff valve 128, additional fluid isprevented from being discharged through the leak. As the bypass valve 42is in the open position, fluid is permitted to flow through the bypasspassage 36 from the bypass inlet 38 on the fluid supply passage 22upstream of the shutoff valve 28 to the bypass outlet 40 on the fluidreturn passage 24 downstream of the return outlet 32.

As such, fluid flows through the bypass passage 36 including the dualorifice venturi valve 144. Due to the venturi effect of the dual orificeventuri valve 144, a pressure in the dual orifice venturi valve 144upstream of the primary orifice 152A and the secondary orifice 152B ishigher than the pressure downstream of the primary orifice 152A and thesecondary orifice 152B due to the decrease in cross-sectional area atthe constricted portion 60. Accordingly, the fluid remaining in thefluid supply passage 22 downstream of the shutoff valve 28 is at ahigher pressure than the pressure at the primary orifice 152A and thefluid moves from the area of high pressure to the area of low pressureto drain the fluid that remains in the fluid supply passage 22 throughthe venturi valve 44 so as to exit through the fluid return passage 24.Further, the fluid remaining in the secondary fluid supply passage 122downstream of the secondary shutoff valve 128 is at a higher pressurethan the pressure at the secondary orifice 152B and the fluid moves fromthe area of high pressure to the area of low pressure to drain the fluidthat remains in the secondary fluid supply passage 122 through the dualorifice venturi valve 144 so as to exit through the fluid return passage24.

As such, the decrease in pressure creates a vacuum at the primaryorifice 152A which allows the fluid that remains in the fluid supplypassage 22 downstream of the shutoff valve 28 to be drawn throughdrawback opening 54 and into the primary orifice 52 via the conduit 46.Fluid drawn through the primary orifice 52 exits the venturi valve 44via the venturi outlet 50 and enters the fluid return passage 24 via thebypass outlet 40. The decrease in pressure creates a vacuum at thesecondary orifice 152B which allows the fluid that remains in thesecondary fluid supply passage 122 downstream of the secondary shutoffvalve 128 to be drawn through secondary drawback opening 154 and intothe secondary orifice 152B via the secondary conduit 146. Fluid drawnthrough the secondary orifice 152B exits the dual orifice venturi valve144 via the venturi outlet 50 and enters the fluid return passage 24 viathe bypass outlet 40. Therefore, the remaining fluid in the fluid supplypassage 22 downstream of the shutoff valve 28 and the remaining fluid inthe secondary fluid supply passage 122 downstream of the secondaryshutoff valve 128 will not discharge through the leak due to the vacuumeffect of the dual orifice venturi valve 144.

In some embodiments, the dual orifice venturi valve 144 not only drawsback the fluid in the fluid supply passage 22 and the secondary fluidsupply passage 122 but any fluid in the device 12 and/or the fluidreturn passage 24 and the secondary fluid return passage 124 that isdownstream of the leak.

In some embodiments, the detection logic 74A is configured to cause theprocessor 72 to determine a presence or absence of a leak in the fluidsupply passage 22, the fluid return passage 24, and the device 12 basedon the signals output from at least one of the supply flowmeter 20A andthe return flowmeter 20B or a leak in the secondary fluid supply passage122, the device 12 (or the secondary device 112), and the secondaryfluid return passage 124 based on the signals output from at least oneof the secondary supply flowmeter 120A and the secondary returnflowmeter 120B.

In a situation in which the processor 72 determines the presence of aleak in one of the fluid supply passage 22, the fluid return passage 24,the cooling part 18, the device inlet 14, or the device outlet 16, basedon output signals from the supply flowmeter 20A and the return flowmeter20B, and determines the absence of a leak in the secondary fluid supplypassage 122, the secondary fluid return passage 124, the secondarycooling part 118, the secondary device inlet 114, or the secondarydevice outlet 116, based on output signals from the secondary supplyflowmeter 120A and the secondary return flowmeter 120B, the controllogic 74B is executed by the processor 72 to control operation of theshutoff valve 28 to switch from the normally open position to the closedposition, the bypass valve 42 from the normally closed position to theopen position, and the primary conduit valve 80 from the normally closedposition to the open position while maintaining the secondary shutoffvalve 128 in the normally open position and the secondary conduit valve180 in the normally closed position.

Accordingly, fluid flows through the bypass passage 36 including thedual orifice venturi valve 144. Due to the venturi effect of the dualorifice venturi valve 144, a pressure in the dual orifice venturi valve144 upstream of the primary orifice 152A and the secondary orifice 152Bis higher than the pressure downstream of the primary orifice 152A andthe secondary orifice 152B due to the decrease in cross-sectional areaat the constricted portion 160. As the fluid remaining in the fluidsupply passage 22 downstream of the shutoff valve 28 is at a higherpressure than the pressure at the primary orifice 152A and the fluidmoves from the area of high pressure to the area of low pressure todrain the fluid that remains in the fluid supply passage 22 through theventuri valve 44 so as to exit through the fluid return passage 24.Specifically, the fluid remaining in the fluid supply passage 22downstream of the shutoff valve 28 flows from the drawback opening 54through the primary conduit valve 80 in the open position and into theprimary orifice 152A of the dual orifice venturi valve 144.

However, as the secondary conduit valve 180 is in the normally closedposition fluid is prevented from flowing through the secondary conduitvalve 180 into the secondary orifice 152B. Further, as the secondaryshutoff valve 128 is in the normally open position fluid from the fluidsupply 30 passes through the fluid supply passage 22 into the secondaryfluid supply passage 122 and through the secondary shutoff valve 128, inthe normally open position, to the secondary device inlet 114.Accordingly, fluid is prevented from passing through the shutoff valve28 as the presence of a leak was detected by the flowmeter unit 20 andfluid is permitted to pass through the secondary shutoff valve 128 asthe absence of a leak was detected by the secondary flowmeter unit 120.

In a situation in which the processor 72 determines the absence of aleak in one of the fluid supply passage 22, the fluid return passage 24,the cooling part 18, the device inlet 14, or the device outlet 16, basedon output signals from the supply flowmeter 20A and the return flowmeter20B, and determines the presence of a leak in the secondary fluid supplypassage 122, the secondary fluid return passage 124, the secondarycooling part 118, the secondary device inlet 114, or the secondarydevice outlet 116, based on output signals from the secondary supplyflowmeter 120A and the secondary return flowmeter 120B, the controllogic 74B is executed by the processor 72 to control operation of thesecondary shutoff valve 128 to switch from the normally open position tothe closed position, the bypass valve 42 from the normally closedposition to the open position, and the secondary conduit valve 180 fromthe normally closed position to the open position while maintaining theshutoff valve 28 in the normally open position and the primary conduitvalve 80 in the normally closed position.

Accordingly, fluid flows through the bypass passage 36 including thedual orifice venturi valve 144. Due to the venturi effect of the dualorifice venturi valve 144, a pressure in the dual orifice venturi valve144 upstream of the primary orifice 152A and the secondary orifice 152Bis higher than the pressure downstream of the primary orifice 152A andthe secondary orifice 152B due to the decrease in cross-sectional areaat the constricted portion 160. As the fluid remaining in the secondaryfluid supply passage 122 downstream of the secondary shutoff valve 128is at a higher pressure than the pressure at the secondary orifice 152B,the fluid moves from the area of high pressure to the area of lowpressure to drain the fluid that remains in the secondary fluid supplypassage 122 through the dual orifice venturi valve 144 so as to exitthrough the fluid return passage 24. Specifically, the fluid remainingin the secondary fluid supply passage 122 downstream of the secondaryshutoff valve 128 flows from the secondary drawback opening 154 throughthe secondary conduit valve 180 in the open position and into thesecondary orifice 152B of the dual orifice venturi valve 144. The fluidthen exits the bypass passage 36 through the bypass outlet 40 and intothe fluid return passage 24.

However, as the primary conduit valve 80 is in the normally closedposition fluid is prevented from flowing through the primary conduitvalve 80 of the conduit 46 into the primary orifice 152A. Further, asthe shutoff valve 28 is in the normally open position fluid from thefluid supply 30 passes through the fluid supply passage 22 through theshutoff valve 28 in the normally open position to the device inlet 14.Accordingly, fluid is prevented from passing through the secondaryshutoff valve 128 as the presence of a leak was detected by thesecondary flowmeter unit 120 and fluid is permitted to pass through theshutoff valve 28 as the absence of a leak was detected by the flowmeterunit 20.

It is appreciated, that the control logic 74B may include an electroniccontrol start time logic and control stop time logic that when executedby the processor 72 switches the bypass valve 42 from the open positionto the normally closed position after a lapse of a predetermined timefrom the switch of the bypass valve 42 from the normally closed positionto the open position.

In addition, the venturi vacuum drawback assembly 10 and the venturivacuum drawback assembly 110 are optionally used to remove fluidremaining in the fluid supply passage 22 and the secondary fluid supplypassage 122, downstream of the shutoff valve 28 and the secondaryshutoff valve 128, when at least one of the shutoff valve 28 and thesecondary shutoff valve 128 are in the closed position to shut off thesupply of fluid to the device 12 and/or the secondary device 112 duringmaintenance of the device 12 and/or the secondary device 112. Forexample, when replacing cooling parts 18A, such as welding tips of arobotic welding device, the shutoff valve 28 is in the closed positionto shut off the flow of fluid to the device 12 and the bypass valve 42is in the open position to drain the remaining fluid to inhibit theremaining fluid from discharging during replacement of the welding tips18A. Similarly, when replacing cooling parts 18A, such as welding tipsof a robotic welding device, the secondary shutoff valve 128 is in theclosed position to shut off the flow of fluid to the secondary device112 and the bypass valve 42 is in the open position to drain theremaining fluid to inhibit the remaining fluid from discharging duringreplacement of the cooling parts 118A, such as welding tips of asecondary robotic welding device.

However, the use of the venturi vacuum drawback assembly 10, the venturivacuum drawback assembly 10′, and the venturi vacuum drawback assembly110 are not limited thereto. It is appreciated, of course, that theventuri vacuum drawback assembly 10, the venturi vacuum drawbackassembly 10′, and the venturi vacuum drawback assembly 110 areapplicable in various other types of recirculating and non-recirculatingcoolant systems illustratively including internal combustion engines,lasers, battery systems, computer system, and other electronic ormechanical components that requires cooling. Moreover, the venturivacuum drawback assembly 10, the venturi vacuum drawback assembly 10′,and the venturi vacuum drawback assembly 110 are applicable in variousother environments illustratively including, but not limited to, fluidtransfer systems used in manufacturing or agriculture. In such fluidtransfer systems, the venturi vacuum drawback assembly 10, the venturivacuum drawback assembly 10′, and the venturi vacuum drawback assembly110 are utilized to direct the flow of fluid through the venturi effectcaused by the venturi valve 44 and the dual orifice venturi valve 144,respectively.

It is appreciated, that the venturi vacuum drawback assembly 10 of FIG.1 includes the conduit valve 80 positioned between the primary orifice52 and the junction 55 and that the venturi vacuum drawback assembly 10′of FIG. 3 includes the primary conduit valve 80 provided on the supplyconduit 46A between the primary orifice 152A and the drawback opening54A and includes the secondary valve 180 provided on the return conduit46B between the secondary orifice 152B and the drawback opening 54B.

It is appreciated, that the fluid controlled by the venturi vacuumdrawback assembly 10, the venturi vacuum drawback assembly 10′, and theventuri vacuum drawback assembly 110 is a cooling fluid such as acoolant including water based coolants and/or natural or synthetic oilbased coolants.

Referring back to FIGS. 1-2 and now referring to FIGS. 6-9 , it shouldbe appreciated that the venturi valve 44 of FIGS. 6-9 is identical tothe venturi valve 44 of FIGS. 1-2 except as noted herein. As such, onlya brief description will be provided of the common features using likenumerals. The venturi valve 44 includes a body 202 that further includesa first end 204A, a second end 204B and a cavity 205 positionedtherebetween. The cavity 205 may be defined by an abutment wall 207A, aupper wall portion 207B, an opposite lower wall portion 207C and anexterior surface 209A of the inlet opening 209 of the inlet passage 62A.It should be appreciated that the abutment wall 207 a is positioned onthe outlet office 64 side of the second constricted positon 60B and theinlet opening 209 of the inlet passage 62A is positioned on the inletorifice 62 of the first constricted portion 60A.

That is, the first constricted portion 60A and the second constrictedportion 60B is positioned between abutment wall 207 a and the exteriorsurface 209A of the inlet opening 209. The first constricted portion 60Aincludes the inlet orifice 62 and the outlet orifice 64. The primaryorifice 52 is positioned at the first constricted portion 60A betweenthe inlet orifice 62 and the outlet orifice 64. As such, the inletorifice 62 is the opening of the first constricted portion 60A that isin fluid communication with the second constricted portion 60B. Thesecond constricted portion 60B is in fluid communication with theventuri inlet 48. The outlet orifice 64 is the opening of the firstconstricted portion 60A that is in communication with the venturi outlet50.

Further, in some embodiments, the body 202 further includes at least oneopening 47. The at least one opening 47 of the body 202 is in fluidcommunication with the conduit 46. As such, fluid within conduit 46enters the opening 47 of the body 202 to enter the venturi valve 44. Insome embodiments, the at least one opening 47 has an inlet portion 49Aand an opposite outlet portion 49B fluidly coupled by an opening passage49C. In some embodiments, the inlet portion 49A includes a chamfer atthe opening 47. The opening passage 49C extends through the body 202 tothe outlet portion 49B, which may be at or within the cavity 205. Insome embodiments, the opening passage 49C extends through the upper wallportion 207B such that the outlet portion 49B is positioned at or withinthe upper wall portion 207B. In other embodiments, the opening passage49C extends through the lower wall portion 207C such that the outletportion 49B is positioned at or within the lower wall portion 207C. Itshould be appreciated that embodiments are not limited to only the upperand lower wall portions 207B, 207C and may also include the openingpassage 49C extending through the abutment wall 207A, the inlet opening209, and the like.

The inlet passage 62A extends between the second constricted portion 60Band the venturi inlet 48. The outlet passage 64A extends between theoutlet orifice 64 and the venturi outlet 50. In some embodiments, theinlet passage 62A and the outlet passage 64A are within the body 202.Further, in some embodiments, an inlet opening 206 of the venture inlet48 may form a portion of the first end 204A of the body 202 and anoutlet opening 208 of the venturi outlet 50 may form a portion of thesecond end 204B of the body 202.

In some embodiments, an insert 210 is positioned in the cavity 205 ofthe body 202 and may be positioned between the abutment wall 207A, theupper wall portion 207B, the lower wall portion 207C, and the exteriorsurface 209A of the inlet opening 209. The insert 210 is configured toenclose at least a portion of both the inlet passage 62A and the outletpassage 64A. In some embodiments, the insert 210 is configured toenclose at least the first constricted portion 60A, the secondconstricted portion 60B, the inlet orifice 62, the outlet orifice 64,the primary orifice 52, and a portion of the inlet passage 62A and theoutlet passage 64A.

In some embodiments, the insert 210 is generally tubular shaped andincludes an exterior surface 212A and an opposite interior surface 212Bformed between an insert first opening 214A and an opposite insertsecond opening 214B defining an insert body 215. As such, the interiorsurface 212B forms an insert inner diameter D5. In some embodiments, theinsert inner diameter D5 is uniform between the insert first opening214A and the insert second opening 214B. In other embodiments, theinsert inner diameter D5 is non-uniform, or irregular, between theinsert first opening 214A and the insert second opening 214B. It shouldbe understood that the insert inner diameter D5 is large enough suchthat the insert 210 may be positioned to enclose, or cover, portions ofthe venturi valve 44, such as the inlet orifice 62, the outlet orifice64 and the first and second constricted portions 60A, 60B, when theinsert 210 is positioned to abut the venturi inlet 48 at the inletpassage 62A, as discussed herein. In some embodiments, the insert firstopening 214A of the insert 210 abuts the venturi inlet 48 at the inletpassage 62A and the insert second opening 214B is positioned at theoutlet passage 64A. As such, it should be understood that the insert 210is in communication with multiple portions of the venturi valve 44, suchas the inlet passage 62A, the outlet passage 64A, the inlet orifice 62,the outlet orifice 64 and the first and second constricted portions 60A,60B.

In some embodiments, the insert body 215 has at least one annular groove216 disposed on the exterior surface 212A. The at least one annulargroove 216 further includes at least one bore 218. In some embodiments,the at least one annular groove 216 includes four bores. The at leastone annular groove 216 has a first width W1, which is greater than asecond width W2 of each of the at least one bore 218. That is, the atleast one annular groove 216 is wider than the at least one bore 218 todirect fluid into the at least one bore 218, as discussed in greaterdetail herein. As such, the at least one annular groove 216 may bealigned with the least one opening 47 of the body 202. In someembodiments, the at least one annular groove 216 is in fluidcommunication with the outlet portion 49B of the at least one opening47. As such, the at least one annular groove 216 is configured to befluidly coupled to the conduit 46, via the least one opening 47 of thebody 202, such that fluid in the conduit 46 enters the at least oneannular groove 216 and travels within the at least one annular groove216 around the tubular insert body 215 of the insert 210 and exits theat least one annular groove 216 through the at least one bore 218.

The at least one bore 218 fluidly couples the exterior surface 212A andthe at least one annular groove 216 of the insert 210 to the primaryorifice 52. As such, fluid from the conduit 46 enters the firstconstricted portion 60A via the least one opening 47 of the body 202,then traveling through, within, or around the at least one annulargroove 216, passing through the at least one bore 218 and into theprimary orifice 52 of the first constricted portion 60A.

In some embodiments, the exterior surface 212A of the insert 210 furtherincludes at least two spaced apart grooves 220. Each groove of the atleast two spaced apart grooves 220 is configured for a sealing material224, such as a gasket or an O-ring, a liquid gasket, and the like. Thesealing material 224 is positioned within each groove at least twospaced apart grooves 220 such that the sealing material 224 is betweenthe exterior surface 212A of the insert 210 and the body 202 of theventuri valve 44. As such, the insert 210 forms a fluid tight, or leakproof connection within the body 202 of the venturi valve 44. Further,the at least two spaced apart grooves 220, including the gasketmaterial, may be positioned on each side of the at least one annulargroove 216.

During operation in which the processor 72 determines the presence of aleak, the venturi vacuum drawback assembly 10 operates to control theflow of fluid from the device 12. Specifically, upon the processor 72determining the presence of a leak based on the one or more signalsoutput from the supply flowmeter 20A and the return flowmeter 20B anddetected by the detection logic 74A, the control logic 74B is executedby the processor 72 to control the shutoff valve 28 from the normallyopen position to the closed position and to control the bypass valve 42from the normally closed position to the open position.

In the closed position, the shutoff valve 28 prevents fluid from flowingfrom the fluid supply 30 through the shutoff valve 28 to the device 12.As fluid is prevented from flowing in the fluid supply passage 22,downstream of the shutoff valve 28, additional fluid is prevented frombeing discharged through the leak. As the bypass valve 42 is in the openposition, fluid is permitted to flow through the bypass passage 36 fromthe bypass inlet 38 on the fluid supply passage 22 upstream of theshutoff valve 28 to the bypass outlet 40 on the fluid return passage 24downstream of the return outlet 32.

As such, fluid flows through the bypass passage 36 including the venturivalve 44. Due to the venturi effect of the venturi valve 44, a pressurein the venturi valve 44 upstream of the primary orifice 52 is higherthan the pressure downstream of the primary orifice 52 due to the changein cross-sectional area at the first constricted portion 60A and thesecond constricted portion 60B. Accordingly, the fluid remaining in thefluid supply passage 22 downstream of the shutoff valve 28 is at ahigher pressure than the pressure at the insert 210 and the pressure ofthe fluid entering the primary orifice 52 and the fluid moves from thearea of high pressure to the area of low pressure to drain the fluidthat remains in the fluid supply passage 22 through the venturi valve 44so as to exit through the fluid return passage 24. Similarly, the fluidremaining in the fluid return passage 24 upstream of the flowmeter is ata higher pressure than the pressure at the insert 210 and into theprimary orifice 52 and the fluid moves from the area of high pressure tothe area of low pressure to drain the fluid that remains in the fluidreturn passage 22 through the venturi valve 44 so as to exit through thefluid return passage 24.

As such, the decrease in pressure creates a vacuum at the primaryorifice 52 allowing the fluid that remains in the fluid supply passage22 downstream of the shutoff valve 28 to be drawn through drawbackopening 54A and into the least one opening 47 of the body 202 via theconduit 46, to travel through, or around, the at least one annulargroove 216 of the insert 210 and then through the at least one bore 218and into the primary orifice 52. Fluid drawn through the primary orifice52 exits the venturi valve 44 via the venturi outlet 50 and enters thefluid return passage 24 via the bypass outlet 40. Therefore, theremaining fluid in the fluid supply passage 22 downstream of the shutoffvalve 28 will not discharge through the leak, such as through the pairof cooling parts 18A, due to the vacuum effect of the venturi valve 44.

Similarly, the decrease in pressure creates a vacuum at the insert 210and, in particular, at the at least one annular groove 216, the at leastone bore 218 and the primary orifice 52, allowing the fluid that remainsin the fluid return passage 24 downstream of the device 12 to be drawnthrough drawback opening 54B and into the at least one opening 47 of thebody 202 via the conduit 46, to travel through, or around, the at leastone annular groove 216 and then through the at least one bore 218 andthrough the primary orifice 52. Fluid drawn through the primary orifice52 exits the venturi valve 44 via the venturi outlet 50 and enters thefluid return passage 24 via the bypass outlet 40. Therefore, theremaining fluid in the fluid return passage 24 downstream of the device12 will not discharge through the leak due to the vacuum effect of theventuri valve 44.

Referring back to FIGS. 3 and 4A-4C, still referring to FIGS. 6-9 andnow referring to FIGS. 10-11 , it should be appreciated that the dualorifice venturi valve 144 of FIGS. 10-11 is identical to the venturivalve 144 of FIGS. 3 and 4A-4C except as noted herein and the insert 210of FIGS. 10-11 is identical to the insert 210 described with respect toFIGS. 6-9 except as noted herein. As such, only a brief description willbe provided of the common features using like numerals. The dual orificeventuri valve 144 is positioned on the bypass passage 36 between thebypass inlet 38 and the bypass valve 42. The dual orifice venturi valve144 further includes a first opening 247 and a second opening 251 of thebody 202. The first opening 247 of the body 202 is in fluidcommunication with the supply conduit 46A and the second opening 251 ofthe body 202 is in fluid communication with the return conduit 46B. Assuch, fluid within the supply conduit 46A enters the first opening 247of the body 202 to enter the venturi valve 144 and fluid within thereturn conduit 46B enters the second opening 251 of the body 202 toenter the venturi valve 144. In some embodiments, the first opening 247has a first inlet portion 249A and an opposite first outlet portion 249Bfluidly coupled by a first opening passage 249C. In some embodiments,the second opening 251 has a second inlet portion 253A and an oppositesecond outlet portion 253B fluidly coupled by a second opening passage253C. In some embodiments, the inlet portions 249A, 253A of the firstand second openings 247, 251 each include a chamfer. The first andsecond opening passages 249C, 253C each extend through the body 202 tothe outlet portions 249B, 253B, which may each be at or within thecavity 205. In some embodiments, the first opening passage 249C extendsthrough the upper wall portion 207B such that the first outlet portion49B is positioned at or within the upper wall portion 207B. Further, insome embodiments, the second opening passage 253C extends through thelower wall portion 207C such that the second outlet portion 253B ispositioned at or within the lower wall portion 207B.

In other embodiments, the first opening passage 249C extends through thelower wall portion 207C such that the first outlet portion 249B ispositioned at or within the lower wall portion 207C and the secondopening passage 253C extends through the upper wall portion 207B suchthat the second outlet portion 253B is positioned at or within the upperwall portion 207B. It should be appreciated that embodiments are notlimited to only the upper and lower wall portions 207B, 207C and mayalso include the first and second opening passages 249C, 253C extendingthrough the abutment wall 207A, the inlet opening 209, and the like.

The dual orifice venturi valve 144 includes the venturi inlet 148, theventuri outlet 150, the primary orifice 152A, the secondary orifice 152Band the insert 210. The primary orifice 152A and the secondary orifice152B are positioned between the venturi inlet 148 and the venturi outlet150. The primary orifice 152A is fluidly connected to the drawbackopening 54A by the supply conduit 46A and the secondary orifice 152B isconnected to the drawback opening 54B by the return conduit 46B. In someembodiments, both the primary orifice 152A and the secondary orifice152B are fluidly connected to the at least one bore 218 within the atleast one annular groove 216 of the insert 210 via the first and secondopenings 247, 251, respectively, in the same manner as described above.A check valve 45 is positioned on the supply conduit 46A between theprimary orifice 152A and the drawback opening 54A and a check valve 45is positioned on the return conduit 46B between the secondary orifice152B and the drawback opening 54B.

The dual orifice venturi valve 144 includes the first constrictedportion 160A and the second constricted portion 160B. The firstconstricted portion 160A includes the inlet orifice 162 and the outletorifice 164. The primary orifice 152A and the secondary orifice 152B arepositioned at the first constricted portion 160A between the inletorifice 162 and the outlet orifice 164. The inlet orifice 162 is thejunction of the first constricted portion 160A and the secondconstricted portion 60B. As such, the inlet orifice 162 is the openingof the first constricted portion 160A that is in communication with thesecond constricted portion 160B. The second constricted portion 60B isin communication with the venturi inlet 148. The outlet orifice 164 isthe opening of the first constricted portion 160A that is incommunication with the venturi outlet 150. In some embodiments, the dualorifice venturi valve 144 includes the inlet passage 162A and the outletpassage 164A. The inlet passage 162A extends between the secondconstricted portion 160B and the venturi inlet 148. The outlet passage164A extends between the outlet orifice 164 and the venturi outlet 150.

In some embodiments, the insert 210 is positioned in the cavity 205 andis configured to enclose at least a portion of at least the firstconstricted portion 160A, the second constricted portion 160B, the inletorifice 162, the outlet orifice 164, the primary orifice 152A, thesecondary orifice 152B and a portion of the inlet passage 162A and theoutlet passage 164A. In some embodiments, the insert first opening 214Aabuts the venturi inlet 148 at the inlet passage 162A and the insertsecond opening 214B is positioned at the outlet passage 164A. In someembodiments, the at least one annular groove 216 disposed on theexterior surface 212A of the insert 210 is in fluid communication withthe first and second openings 247, 251 to fluidly couple the supplyconduit 46A and the return conduit 46B to the insert 210. In otherembodiments, the insert 210 has at least two annular grooves, one influid communication with the first opening 247 and the other annulargroove in fluid communication with the second opening 251. Further, insome embodiments, one bore of the at least one bore 218 is in fluidcommunication with the primary orifice 152A and another one bore of theat least one bore 218 is in fluid communication with the secondaryorifice 152B.

During operation in which the processor 72 determines the presence of aleak, the venturi vacuum drawback assembly 10 operates to control theflow of fluid from the device 12. Specifically, upon the processor 72determining the presence of a leak based on the one or more signalsoutput from the supply flowmeter 20A and the return flowmeter 20B anddetected by the detection logic 74A, the control logic 74B is executedby the processor 72 to control the shutoff valve 28 from the normallyopen position to the closed position and to control the bypass valve 42from the normally closed position to the open position.

In some embodiments, the processor 72 executes the control logic 74B toswitch the bypass valve 42 from the normally closed position to the openposition simultaneously with the switching of the shutoff valve 28 fromthe normally open position to the closed position. In some embodiments,the processor 72 executes the control logic 74B to switch the bypassvalve 42 from the normally closed position to the open position after anelapse of a preset time period after switching of the shutoff valve 28from the normally open position to the closed position.

In the closed position, the shutoff valve 28 prevents fluid from flowingfrom the fluid supply 30 through the shutoff valve 28 to the device 12.As fluid is prevented from flowing in the fluid supply passage 22,downstream of the shutoff valve 28, additional fluid is prevented frombeing discharged through the leak. As the bypass valve 42 is in the openposition, fluid is permitted to flow through the bypass passage 36 fromthe bypass inlet 38 on the fluid supply passage 22 upstream of theshutoff valve 28 to the bypass outlet 40 on the fluid return passage 24downstream of the return outlet 32.

As such, fluid flows through the bypass passage 36 including the dualorifice venturi valve 144. Due to the venturi effect of the dual orificeventuri valve 144, a pressure in the dual orifice venturi valve 144upstream of the primary orifice 152A and the secondary orifice 152B ishigher than the pressure downstream of the primary orifice 152A due tothe change in cross-sectional area at the first constricted portion 160Aand the second constricted portion 160B. Accordingly, the fluidremaining in the fluid supply passage 22 downstream of the shutoff valve28 is at a higher pressure than the pressure at the primary orifice 152Aand the fluid moves from the area of high pressure to the area of lowpressure to drain the fluid that remains in the fluid supply passage 22through the dual orifice venturi valve 144 so as to exit through thefluid return passage 24. Similarly, the fluid remaining in the fluidreturn passage 24 upstream of the flowmeter 20 is at a higher pressurethan the pressure at the secondary orifice 152B and the fluid moves fromthe area of high pressure to the area of low pressure to drain the fluidthat remains in the fluid return passage 24 through the dual orificeventuri valve 144 so as to exit through the fluid return passage 24.

As such, the decrease in pressure creates a vacuum at the primaryorifice 152A allowing the fluid that remains in the fluid supply passage22 downstream of the shutoff valve 28 to be drawn through drawbackopening 54A and into the at least one annular groove 216 of the insert210, via the supply conduit 46A and through the first opening 247, totravel through, within, or around, the at least one annular groove 216and then through the at least one bore 218 and into the primary orifice152A. Fluid drawn through the primary orifice 152A exits the dualorifice venturi valve 144 via the venturi outlet 50 and enters the fluidreturn passage 24 via the bypass outlet 40. Therefore, the remainingfluid in the fluid supply passage 22 downstream of the shutoff valve 28will not discharge through the leak due to the vacuum effect of theventuri valve 44.

Similarly, the decrease in pressure creates a vacuum at the secondaryorifice 152B allowing the fluid that remains in the fluid return passage24 downstream of the device 12 to be drawn through drawback opening 54Band into the at least one annular groove 216 of the insert 210, via thereturn conduit 46B and through the second opening 251, to travelthrough, within, or around, the at least one annular groove 216 and thenthrough a different, or another one of the at least one bores 218 andinto the secondary orifice 152B. Fluid drawn through the secondaryorifice 152B exits the dual orifice venturi valve 144 via the venturioutlet 50 and enters the fluid return passage 24 via the bypass outlet40. Therefore, the remaining fluid in the fluid return passage 24downstream of the device 12 will not discharge through the leak due tothe vacuum effect of the venturi valve 44.

Referring back to FIG. 5 and still referring to FIGS. 10-11 , theoperation of the venturi vacuum drawback assembly 110 with the insert210 will be described. It should be appreciated that the dual orificeventuri valve 144 of FIGS. 10-11 is identical to the venturi valve 144of FIGS. 4A-4C and 5 .

In the closed position, the shutoff valve 28 prevents fluid from flowingfrom the fluid supply 30 through the shutoff valve 28 to the device 12,and the secondary shutoff valve 128 prevents fluid from flowing from thesecondary fluid supply passage 122 through the secondary shutoff valve128 to the device. As fluid is prevented from flowing in the fluidsupply passage 22, downstream of the shutoff valve 28, and fluid isprevented from flowing in the secondary fluid supply passage 122,downstream of the secondary shutoff valve 128, additional fluid isprevented from being discharged through the leak. As the bypass valve 42is in the open position, fluid is permitted to flow through the bypasspassage 36 from the bypass inlet 38 on the fluid supply passage 22upstream of the shutoff valve 28 to the bypass outlet 40 on the fluidreturn passage 24 downstream of the return outlet 32.

As such, fluid flows through the bypass passage 36 including the dualorifice venturi valve 144. Due to the venturi effect of the dual orificeventuri valve 144, a pressure in the dual orifice venturi valve 144upstream of the primary orifice 152A and the secondary orifice 152B ishigher than the pressure downstream of the primary orifice 152A and thesecondary orifice 152B due to the decrease in cross-sectional area atthe constricted portion 60. Accordingly, the fluid remaining in thefluid supply passage 22 downstream of the shutoff valve 28 is at ahigher pressure than the pressure at the primary orifice 152A and thefluid moves from the area of high pressure to the area of low pressureto drain the fluid that remains in the fluid supply passage 22 throughthe venturi valve 44 so as to exit through the fluid return passage 24.Further, the fluid remaining in the secondary fluid supply passage 122downstream of the secondary shutoff valve 128 is at a higher pressurethan the pressure at the secondary orifice 152B and the fluid moves fromthe area of high pressure to the area of low pressure to drain the fluidthat remains in the secondary fluid supply passage 122 through the dualorifice venturi valve 144 so as to exit through the fluid return passage24.

As such, the decrease in pressure creates a vacuum at the primaryorifice 152A which allows the fluid that remains in the fluid supplypassage 22 downstream of the shutoff valve 28 to be drawn throughdrawback opening 54 and into the at least one annular groove 216 of theinsert 210, via the conduit 46 and the first opening 247, to travelthrough, or around, the at least one annular groove 216 through the atleast one bore 218 and into the primary orifice 152A. Fluid drawnthrough the primary orifice 152A exits the venturi valve 44 via theventuri outlet 50 and enters the fluid return passage 24 via the bypassoutlet 40. The decrease in pressure creates a vacuum at the secondaryorifice 152B which allows the fluid that remains in the secondary fluidsupply passage 122 downstream of the secondary shutoff valve 128 to bedrawn through secondary drawback opening 154 into the at least oneannular groove 216 of the insert 210, via the secondary conduit 146 andthe second opening 251, to travel through, within, or around, the atleast one annular groove 216 through the at least one bore 218 and intothe secondary orifice 152B. Fluid drawn through the secondary orifice152B exits the dual orifice venturi valve 144 via the venturi outlet 50and enters the fluid return passage 24 via the bypass outlet 40.Therefore, the remaining fluid in the fluid supply passage 22 downstreamof the shutoff valve 28 and the remaining fluid in the secondary fluidsupply passage 122 downstream of the secondary shutoff valve 128 willnot discharge through the leak due to the vacuum effect of the dualorifice venturi valve 144.

In a situation in which the processor 72 determines the presence of aleak in one of the fluid supply passage 22, the fluid return passage 24,the cooling part 18, the device inlet 14, or the device outlet 16, basedon output signals from the supply flowmeter 20A and the return flowmeter20B, and determines the absence of a leak in the secondary fluid supplypassage 122, the secondary fluid return passage 124, the secondarycooling part 118, the secondary device inlet 114, or the secondarydevice outlet 116, based on output signals from the secondary supplyflowmeter 120A and the secondary return flowmeter 120B, the controllogic 74B is executed by the processor 72 to control operation of theshutoff valve 28 to switch from the normally open position to the closedposition, the bypass valve 42 from the normally closed position to theopen position, and the primary conduit valve 80 from the normally closedposition to the open position while maintaining the secondary shutoffvalve 128 in the normally open position and the secondary conduit valve180 in the normally closed position.

Accordingly, fluid flows through the bypass passage 36 including thedual orifice venturi valve 144. Due to the venturi effect of the dualorifice venturi valve 144, a pressure in the dual orifice venturi valve144 upstream of the primary orifice 152A and the secondary orifice 152Bis higher than the pressure downstream of the primary orifice 152A andthe secondary orifice 152B due to the decrease in cross-sectional areaat the constricted portion 160. As the fluid remaining in the fluidsupply passage 22 downstream of the shutoff valve 28 is at a higherpressure than the pressure at the primary orifice 152A and the fluidmoves from the area of high pressure to the area of low pressure todrain the fluid that remains in the fluid supply passage 22 through theventuri valve 44 so as to exit through the fluid return passage 24.Specifically, the fluid remaining in the fluid supply passage 22downstream of the shutoff valve 28 flows from the drawback opening 54and through the supply conduit 46, through the primary conduit valve 80in the open position and into the at least one annular groove 216 viathe first opening 247, to travel through, within, or around, the atleast one annular groove 216 and then through the at least one bore 218and into the primary orifice 152A of the dual orifice venturi valve 144.

In a situation in which the processor 72 determines the absence of aleak in one of the fluid supply passage 22, the fluid return passage 24,the cooling part 18, the device inlet 14, or the device outlet 16, basedon output signals from the supply flowmeter 20A and the return flowmeter20B, and determines the presence of a leak in the secondary fluid supplypassage 122, the secondary fluid return passage 124, the secondarycooling part 118, the secondary device inlet 114, or the secondarydevice outlet 116, based on output signals from the secondary supplyflowmeter 120A and the secondary return flowmeter 120B, the controllogic 74B is executed by the processor 72 to control operation of thesecondary shutoff valve 128 to switch from the normally open position tothe closed position, the bypass valve 42 from the normally closedposition to the open position, and the secondary conduit valve 180 fromthe normally closed position to the open position while maintaining theshutoff valve 28 in the normally open position and the primary conduitvalve 80 in the normally closed position.

Accordingly, fluid flows through the bypass passage 36 including thedual orifice venturi valve 144. Due to the venturi effect of the dualorifice venturi valve 144, a pressure in the dual orifice venturi valve144 upstream of the primary orifice 152A and the secondary orifice 152Bis higher than the pressure downstream of the primary orifice 152A andthe secondary orifice 152B due to the decrease in cross-sectional areaat the constricted portion 160. As the fluid remaining in the secondaryfluid supply passage 122 downstream of the secondary shutoff valve 128is at a higher pressure than the pressure at the secondary orifice 152B,the fluid moves from the area of high pressure to the area of lowpressure to drain the fluid that remains in the secondary fluid supplypassage 122 through the dual orifice venturi valve 144 so as to exitthrough the fluid return passage 24. Specifically, the fluid remainingin the secondary fluid supply passage 122 downstream of the secondaryshutoff valve 128 flows from the secondary drawback opening 154, throughthe secondary conduit 146, through the secondary conduit valve 180 inthe open position and into the at least one annular groove 216 via thesecond opening 251, to travel through, or around, the at least oneannular groove 216 and then through the at least one bore 218 and intothe secondary orifice 152B of the dual orifice venturi valve 144. Thefluid then exits the bypass passage 36 through the bypass outlet 40 andinto the fluid return passage 24.

While particular embodiments and aspects of the present disclosure havebeen illustrated and described herein, various other changes andmodifications can be made without departing from the spirit and scope ofthe disclosure. Moreover, although various aspects have been describedherein, such aspects need not be utilized in combination. It istherefore intended that the appended claims cover all such changes andmodifications that are within the scope of the embodiments shown anddescribed herein.

The invention claimed is:
 1. A venturi valve comprising: a body having afirst end, a second end, and a cavity positioned therebetween; an inletpositioned at the first end; an outlet opposite of the inlet andpositioned at the second end; a passage positioned between the inlet andthe outlet and extending through the body fluidly coupling the inlet tothe outlet; and an opening passage; and an insert positioned within thecavity and between the inlet and the outlet such that the insertencloses at least a portion of the passage, the insert includes an inletpassage, a constricted portion having a first constricted portion, anopposite second constricted portion and a primary orifice positionedbetween the first constricted portion and the second constricted portionand in fluid communication with the opening passage such that theprimary orifice permits fluid to enter the constricted portion, thefirst constricted portion having an inlet orifice and the secondconstricted portion having an outlet orifice, the inlet passage abutsthe inlet orifice and tapers in a direction from the inlet to the inletorifice, the passage fluidly coupling the first constricted portion, thesecond constricted portion, and the inlet passage to the inlet and theoutlet, the outlet orifice having an outlet diameter that is greaterthan an inlet diameter of the inlet orifice, the passage in fluidcommunication with the first constricted portion and the secondconstricted portion fluidly coupling the first constricted portion andthe second constricted portion to the inlet and the outlet, the inserthaving an exterior surface and an opposite interior surface, the inserthas an annular groove disposed on the exterior surface, the annulargroove has at least one bore that extends orthogonal to an axis of theinsert, the annular groove fluidly couples the opening passage to the atleast one bore.
 2. The venturi valve of claim 1, wherein an area of theoutlet is equal to or greater than a sum of an area of the primaryorifice and an area of the inlet.
 3. The venturi valve of claim 1,further comprises: a conduit fluidly coupled to the insert, wherein theinsert is generally tubular shaped, the at least one bore permits fluidfrom the conduit to travel through the annular groove and through the atleast one bore and into the primary orifice of the constricted portion.4. The venturi valve of claim 3, wherein the insert is positioned toenclose at least the inlet orifice, the outlet orifice and theconstricted portion.
 5. The venturi valve assembly of claim 4, whereinthe exterior surface of the insert further includes at least two spacedapart grooves, each groove of the at least two grooves is configured fora sealing member positioned between each groove of the pair of groovesand the body.
 6. The venturi valve of claim 5, wherein the constrictedportion further includes a secondary orifice, the annular groove and theat least one bore fluidly couples the exterior surface of the insert tothe secondary orifice to permit fluid from the secondary orifice toenter the constricted portion.
 7. A dual orifice venturi valvecomprising: a body having a first end, a second end, and a cavitypositioned therebetween; an inlet positioned at the first end; an outletopposite of the inlet and positioned at the second end; a passagepositioned between the inlet and the outlet and extending through thebody fluidly coupling the inlet to the outlet; a first opening passage;a second opening passage; and an insert positioned within the cavity andbetween the inlet and the outlet such that the insert encloses a portionof the passage, the insert includes an inlet passage, a constrictedportion having a first constricted portion, an opposite secondconstricted portion, a primary orifice, and a secondary orifice, theprimary orifice is positioned between the first constricted portion andthe second constricted portion and is in fluid communication with thefirst opening passage such that the primary orifice permits fluid toenter the constricted portion, the secondary orifice is positionedbetween the first constricted portion and the second constricted portionand is in fluid communication with the second opening passage such thatthe secondary orifice permits fluid to enter the constricted portion,the first constricted portion having an inlet orifice and the secondconstricted portion having an outlet orifice, the inlet passage abutsthe inlet orifice and tapers in a direction from the inlet to the inletorifice, the passage fluidly coupling the first constricted portion, thesecond constricted portion, and the inlet passage to the inlet and theoutlet, the outlet orifice having an outlet diameter that is greaterthan an inlet diameter of the inlet orifice, the passage in fluidcommunication with the first constricted portion and the secondconstricted portion fluidly coupling the first constricted portion andthe second constricted portion to the inlet and the outlet, the inserthaving an exterior surface and an opposite interior surface, the inserthas an annular groove disposed on the exterior surface, the annulargroove has at least one bore that extends orthogonal to an axis of theinsert, the annular groove fluidly couples the first opening passage andthe second opening passage to the at least one bore.
 8. The dual orificeventuri valve of claim 7, further comprises: a primary conduit fluidlycoupled to the insert; a secondary conduit fluidly coupled to theinsert, wherein the insert is generally tubular shaped, the annulargroove permits fluid from the primary and secondary conduits to travelthrough the annular groove and through the at least one bore and enterthe first constricted portion via either the primary and secondaryorifices.
 9. The dual orifice venturi valve of claim 8, wherein theinsert is positioned to enclose at least the inlet orifice, the outletorifice and the first and second constricted portions.
 10. The dualorifice venturi valve of claim 9, wherein the exterior surface of theinsert further includes at least two spaced apart grooves, each grooveof the at least two grooves is configured for a sealing member to meshbetween each one of the at least two grooves and the body.
 11. A venturivacuum system for controlling a flow of a fluid from a device, theventuri vacuum system comprising: a fluid supply passage that suppliesthe fluid to the device; a fluid return passage that returns the fluidfrom the device; a shutoff valve positioned on the fluid supply passage;a bypass passage includes an inlet and an outlet, the inlet connected tothe fluid supply passage upstream of the shutoff valve, and the outletconnected to the fluid return passage; a bypass valve positioned on thebypass passage; and a venturi valve positioned on the bypass passageupstream of the bypass valve, the venturi valve includes a body having aventuri inlet, a venturi outlet and a cavity positioned therebetween, aprimary orifice positioned between the venturi inlet and the venturioutlet, a venturi passage positioned between the venturi inlet and theventuri outlet to fluidly couple the venturi inlet the venturi outlet,and an insert positioned within the cavity of the body, the insertconfigured to enclose a portion of the passage, the primary orifice isconnected to a drawback opening on the fluid supply passage by aconduit, the drawback opening of the fluid supply passage is positioneddownstream of the shutoff valve.
 12. The venturi vacuum system of claim11, wherein the venturi passage includes a constricted portionpositioned between the venturi inlet and the venturi outlet, theconstricted portion is in fluid communication with the primary orifice,the venturi inlet has an inlet orifice at the constricted portion, theventuri outlet has an outlet orifice at the constricted portion, theoutlet orifice having an outlet diameter that is greater than an inletdiameter of the inlet orifice, and wherein an area of the outlet isequal to or greater than a sum of an area of the primary orifice and anarea of the inlet.
 13. The venturi vacuum system of claim 12, whereinthe insert is generally tubular shaped having an exterior surface and anopposite interior surface, the insert has an annular groove disposed onthe exterior surface, the annular groove has at least one bore thatfluidly couples the exterior surface to the constricted portion topermit fluid from the conduit to enter the annular groove and throughthe at least one bore and into the constricted portion via the primaryorifice.
 14. The venturi vacuum system of claim 13, wherein the shutoffvalve is configured to be switchable between a normally open positionand a closed position, in the normally open position fluid is permittedto flow through the shutoff valve to the device, and in the closedposition fluid is inhibited from flowing through the shutoff valve,wherein the bypass valve is movable between a normally closed positionand an open position, in the normally closed position fluid flowing fromthe fluid supply passage is inhibited from flowing through the bypassvalve to the fluid return passage, in the open position fluid flowingfrom the fluid supply passage is permitted to flow through the bypassvalve to the fluid return passage, and wherein switching of the shutoffvalve from the normally open position to the normally closed positionand switching of the bypass valve from the normally closed position tothe open position, fluid flowing through the inlet orifice and at theconstricted portion create a vacuum at the primary orifice of theventuri valve that draws fluid remaining in the fluid supply passagedownstream of the shutoff valve through the drawback opening in thefluid supply passage and into the conduit such that the fluid in theconduit passes through the primary orifice to flow within at least oneof the plurality of annular grooves and through the at least one bore toenter the constricted portion.
 15. The venturi valve of claim 1, whereinthe opening passage extends from an exterior surface of the body to thecavity.
 16. The dual orifice venturi valve of claim 7, wherein the firstopening passage extends from an exterior surface of the body to thecavity.
 17. The dual orifice venturi valve of claim 16, wherein thesecond opening passage extends from the exterior surface of the body tothe cavity.